Intrinsic and extrinsic influences on ecological communities

Resum

Ecologists and evolutionary biologists have sought to understand geographic variation in the diversity of species ever since the great natural history explorations of the 19th Century and the subsequent development of ecology and evolution as scientific disciplines. Early insights, beginning with Darwin and Wallace, focused on the role of competition in limiting species coexistence within communities, but ecologists have gradually shifted to a more regional perspective that includes the processes of species production and extinction within regions. Recent observations, including the evolutionary lability of distribution and abundance, and the absence of a clear signal of competition impacts on populations of close relatives, suggest that coevolutionary relationships between pathogens and their hosts might be responsible for observed variation in distribution and abundance, and also drive the diversification of species within regions. Margalef’s emphasis on observing nature closely, and paying attention to the implications of patterns for underlying processes, had a strong influence on me as a graduate student 50 years ago, and continues to be valid. [Contrib Sci 12(1):27-34 (2016)]

Keywords: species diversity · competition · population distribution and abundance · pathogen-host coevolution · Ramon Margalef Prize 2015